Huh? goodjob, you sound like mastercard. i don't understand why people need two(multiple) nicks when they can't  convey a message clearly through either.

so there is a pain factor here. and it's same with all drugs if he's not going to survive with each of them.

i still stick with my previous suggestion, ie. go with option B. Buy as much time as possible and hope for the advent of better treatment technologies with time. Drug C has 80% chances of failure and it's not worth going for risk when the stake is that high (chances of survival being just 20% on paper) and when it's the freakin question of life and death.

Slackdemic bro,
I understand what you're saying. But even if it's an ethical question with pain involved during medication, i am not sure it's worth going with option C in this particular case as there is not much point in waiting and letting him live without medication. First thing, his conditions will deteriorate without medication, and secondly the 10 years that the docs claim he might live is just an approximation. So as you said, he might need medication before the end of first 10 years, say after 7 years to be in safe side. Therefore, you are looking at 15 years of life with B vs. 7 to 8 years with C if he does not survive (which could be 80% true).

goktey,
LOL! you sound like a gambler. dude, this ain't no poker, someone is dying here for heaven's sake.